File 0174-Correct-code-module_status-1-for-BEAM-files-in-archi.patch of Package erlang

From 0fe4106fbcc924f245ac8afb69db1625ebbb6ebe Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= <bjorn@erlang.org>
Date: Tue, 22 Mar 2022 06:46:17 +0100
Subject: [PATCH] Correct `code:module_status/1` for BEAM files in archives

`code:module_status/1` would always return `modified` for BEAM
file loaded from an archive file.

Closes #5801
---
 lib/kernel/src/code.erl | 32 +++++++++++++++++++++++---------
 1 file changed, 23 insertions(+), 9 deletions(-)

diff --git a/lib/kernel/src/code.erl b/lib/kernel/src/code.erl
index 71a570fa7b..b45b55768a 100644
--- a/lib/kernel/src/code.erl
+++ b/lib/kernel/src/code.erl
@@ -1048,20 +1048,20 @@ module_status(Module) ->
 %% Note that we don't want to go via which/1, since it doesn't look at the
 %% disk contents at all if the module is already loaded.
 module_status(Module, PathFiles) ->
-    case code:is_loaded(Module) of
+    case is_loaded(Module) of
         false -> not_loaded;
         {file, preloaded} -> loaded;
         {file, cover_compiled} ->
-            %% cover compilation loads directly to memory and does not
-            %% create a beam file, so report 'modified' if a file exists
+            %% Cover compilation loads directly to memory and does not
+            %% create a beam file, so report 'modified' if a file exists.
             case which(Module, PathFiles) of
                 non_existing -> removed;
                 _File -> modified
             end;
         {file, []} -> loaded;  % no beam file - generated code
-        {file, OldFile} when is_list(OldFile) ->
-            %% we don't care whether or not the file is in the same location
-            %% as when last loaded, as long as it can be found in the path
+        {file, [_|_]} ->
+            %% We don't care whether or not the file is in the same location
+            %% as when last loaded, as long as it can be found in the path.
             case which(Module, PathFiles) of
                 non_existing -> removed;
                 Path ->
@@ -1076,10 +1076,24 @@ module_status(Module, PathFiles) ->
 %% be reloaded; does not care about file timestamps or compilation time
 module_changed_on_disk(Module, Path) ->
     MD5 = erlang:get_module_info(Module, md5),
-    MD5 =/= beam_file_md5(Path).
+    MD5 =/= beam_file_md5(Module, Path).
+
+beam_file_md5(Module, Path) ->
+    case do_beam_file_md5(Path) of
+        MD5 when is_binary(MD5) ->
+            MD5;
+        undefined ->
+            %% This module is probably embedded in an archive.
+            case get_object_code(Module) of
+                {Module, Code, _Path} ->
+                    do_beam_file_md5(Code);
+                error ->
+                    undefined
+            end
+    end.
 
-beam_file_md5(Path) ->
-    case beam_lib:md5(Path) of
+do_beam_file_md5(PathOrCode) ->
+    case beam_lib:md5(PathOrCode) of
         {ok,{_Mod,MD5}} -> MD5;
         _ -> undefined
     end.
-- 
2.34.1